This invention relates to ignition coils for spark-ignited internal combustion engines, and deals more particularly with improvements in the construction of such coils.
Although the ignition coil of this invention may be used with various different types of spark-ignited internal combustion engines, it is particularly well adapted for use with relatively small single cylinder or double cylinder engines such as conventionally used to power chain saws, lawn mowers, snow blowers, and similar tools requiring low horsepower drives. Such engines are usually made in large numbers for highly competitive markets so it is desirable that the cost of manufacture be reduced as far as possible. On the other hand, such engines are often used in applications requiring their frequent stopping and starting and, therefore, their ignition systems should be especially reliable to insure ease of starting. In keeping with these requirements, the ignition coil of this invention is one which may be made at relatively low cost since it is made of a small number of parts which may be assembled in accordance with an efficient method comprising another aspect of the invention. Furthermore, the ignition coil of the invention, despite its economy and ease of manufacture, is one having high reliability and operating efficiency together with long service life. It further, with little change, may be made either single ended or double ended with regard to its secondary winding. The single ended construction may be used with single cylinder engines or with multi-cylinder engines having a distributor in the ignition system. The double ended construction is particularly well adapted for use with two cylinder engines which do not include distributors in their ignition systems.
Other objects and advantages of the invention will be apparent from the following detailed description thereof and from the appended drawings forming a part thereof.